1. Isomers, Lewis Structures, Connectivity and Sigma Bonds

2. Breathalyzer Test for Ethanol (Investigate This 5.1) CH 3 CH 2 OH + Cr 2 O 7 2- + H 2 O + Cr 3+ orange H 2 SO 4 unbalanced rxn green before rxn after rxn with ethanol H 3 CH

3. Does Rxn Work For Other Alcohols (5.1)? n-butanol iso-butanol sec-butanol tert-butanol C 4 H 10 O

4. Breathalyzer® Reagent Before Adding Alcohols (5.1)

5. Results of Breathalyzer® Tests on Various Alcohols (5.1) n-butyl alcohol iso-butyl alcohol blank (acetone only) ethanol sec-butyl alcohol tert-butyl alcohol

6. Connectivity Matters: Rxn Does Not Work with tert-Butanol General Rxn: R 2 CHOH + Cr 2 O 7 2- + H 2 O + Cr 3+ H 2 SO 4 unbalanced = R 2 CHOH (no H is directly bound to the hydroxyl C) tert-butanol

7. Molecular Orbital Theory e- in atoms exist in quantized E states atomic orbitals (AOs) e- in molecules exist in quantized E states molecular orbitals(MOs) MOs form from combination of AOs and belong to molecule as a whole

8. Forming MOs e- in AO is a wave e- waves from two different AOs can interfere constructive (waves added) destructive (waves subtracted) result of interference = two MOs

9. Forming H 2 MOs from H AOs  * is higher E than AOs  is lower E than AOs one AO from each H atom H H two MOs of H 2 Molecule H - H

10. H 2 forms because e-’s are at lower E in MOs vs the parent AOs MO Energy Level Diagram (“MO Diagram”) for H 2 The bonding e- pair ‘occupies’ this  orbital No e- ‘occupies’ this  orbital.